A technology has been proposed in which cells for transplantation are inserted into a cartilage deficient site in a joint (transplantation site) and the deficient site is restored through regeneration of the transplanted cells (Brittberg M., Treatment of deep cartilage defects in the knee with autologous chondrocyte transplantation. N Engl J Med 1994; 331: 889-95). One example of cells used for such transplantation is myeloid stem cell (mesenchymal stem cell, bone marrow stem cell, bone marrow stromal cell; hereinafter called “MSC”).
Here, a specific transplantation method will be explained taking an example of a transplantation using a cell plug for cartilage defect in a joint (WO 2005/11765). First, a hole of a predetermined size is formed in a cartilage-deficient site. Then, an autologous cell plug is inserted into the hole. For this purpose, the hole formed in the cartilage should be almost the same shape and size as the cell plug. When the cell plug is inserted, the plug induces the excretion of regeneration factors from the healthy sites surrounding the deficient site as time passes, causing the restoration of the deficient site.
However, since cell plugs themselves are aggregations of cells, they are very soft, and since tweezers or the like are used when technicians insert them into the holes formed in cartilage, it is very difficult to determine the amount of force needed when gripping cell plugs. Further, due to this reason, sometimes cell plugs cannot be fixed at the optimum depth, and sometimes there are cases in which a gap remains between the cell plugs and healthy cells because tweezers must be withdrawn. In addition, the cell plug sometimes becomes damaged when direct force is exerted on the cell plug to push it into a cell-deficient site.